PS:
[rocketmouse at archlinux ~]$ uname
Linux
[rocketmouse at archlinux ~]$ man date | grep %V
%G year of ISO week number (see %V); normally useful only with %V
%V ISO week number, with Monday as first day of week (01..53)
[rocketmouse at archlinux ~]$ date -u +%V$(uname)
39Linux
[rocketmouse at archlinux ~]$
;)